1. Field of the Invention
The present invention relates to a trocar for introducing an endoscope, A therapeutic instrument and the like into a living body during operation. A trocar according to the invention is suited to, for example, endoscopic surgical operation.
2. Description of the Related Art
Various types of trocars for introducing endoscopes, therapeutic instruments and the like into living bodies are known.
Japanese Utility Model Registration No. 3024069 discloses an art of providing a balloon-like stopper on a trocar to prevent the trocar from coming off.
Japanese Patent Laid-Open No. 28666/1997 discloses an art of preventing a trocar from coming off, by expanding an expanding portion in a body cavity.